Manchester United goalkeeper David De Gea believes he has come of age since moving to the Premier League 18 months ago.

De Gea, 22, has gone through his fair share of hard times since arriving at Old Trafford in June 2011, with some critics doubting whether United have had value for money from the £17.8 million they spent on the player.

However, the former Atletico Madrid man has hit real form in recent months and has nailed down the No. 1 shirt at the club, having previously shared the role with Anders Lindegaard.

"I've changed a lot in Manchester. I've spent two years in their football culture and it makes you change," De Gea is quoted as saying in the Daily Star.

"I'm more mature as a person and a player. I'm a very different person from when I arrived in England."

De Gea's form has been noticed by Spain coach Vicente Del Bosque, who called him up to his squad for the upcoming World Cup qualifiers against Finland and France.

The keeper has yet to win a cap for his country but was drafted into the squad to provide cover for the injured Iker Casillas.

"This is a special moment for me and a big step in my career," De Gea said. "I want to enjoy this and learn from my team-mates, who are my and many other people's idols.

"It's a pity Iker Casillas is out. We all know he is our captain and a legend but I'm happy to be here, even if it's because of his injury."